The present invention relates to graphene and, more particularly, to systems and methods for the scalable manufacture of continuous graphene sheets.
Graphene is an individual layer of carbon having a hexagonal bonding structure in a one-atom thick sheet. Graphene is shown to have great potential in a wide range of applications from photovoltaics and electronics to desalination membranes. Despite the well-recognized potential of graphene for numerous applications, a reliable technology for the scaled up production of graphene remains a bottleneck in the transition from graphene research to the development of practically viable graphene devices.
One known technique for graphene production includes chemical vapor deposition (CVD). According to this method, a catalytic substrate is annealed in a reducing atmosphere. After annealing, the catalytic substrate is exposed to a carbon source. A variety of organic gases and solids can be used as a carbon source for graphene growth, with methane gas being a widely used precursor.
Despite the existence of the above method for synthesizing graphene, there remains a continued need for systems and methods for the scalable manufacture of graphene, including continuous graphene sheets. In particular, there remains a continued need for a method of forming continuous graphene sheets having controllable properties, including nucleation density, domain size, and grain structure. The challenges of a low pressure CVD approach include: difficulty in feeding the catalyst foil into a low pressure reactor, severe evaporation of catalyst and requirement of a vacuum system compatible with flammable precursor gases. Presented here, atmospheric pressure CVD is free of these challenges and thus is more suitable for applications in mass production of graphene by CVD.